Mufflers for internal combustion engines, such as stationary, small horsepower engines commonly used in portable generators and lawn mowers and the like, are known in the art. Typically, these mufflers comprise single, elongated tubes housed within bulky, metallic shells, which change the direction of the sound waves to reduce the noise of the escaping gaseous products of combustion.
The mufflers of the prior art have not been satisfactory since they have been generally unable to reduce the difference in sound pressure levels between the input and exhaust sides of the muffler by more than a few decibels. As a result, the mufflers of the prior art have not been able to compete with imported mufflers which have been designed to comply with the stricter standards of the European Common Market. A need therefore exists for a muffler which is capable of significantly reducing the sound pressure levels of the exhaust gases of internal combustion engines, compete with the quieter import models, and is capable of meeting the stricter standards of the European Common Market.